Systematic Studies On Phaenosperma And Sphaerocaryum

Phaenosperma, a taller perennial herbs, belonging to Gramineae, is widely distributed in China. Sphaerocaryum, an annual herb with a smaller size, is most distributed in the countries of southeast in Asia. Both of them are only contained one kind of plant and their systematic location is still controversial.Our article through to show Phytolith morphological, micromorphological of glume, analysis comprehensive characters of two relatives of plant of Phaenosperma and Sphaerocaryum and combined with molecular biology methods to provide sufficient evidence to solve the problem of systematic location controversial.We select 62 plant leaves in different species of Phaenosperma, Sphaerocaryum and observe their characters under a microscope. We divided Phytolith into five basic types, and eight kinds of sub-types, according to their arrangement, containing particles, and the analysis of the length-width ratio. By the result, we find that the shape of Phytolith in Phaenosperma existing more different from type V and type II belongs to type IV. Phytolith in Sphaerocaryum are different from sub-type c and type IV, meet the standard of sub-type e in type III.Study on glume of 51 species in Phaenosperma, Sphaerocaryum and observe their characters using electron microscope,We divided glume micromorphological into four types and nine sub-types according to the character of their length cells,short cells, silica bodies, stomata, prickles, micro hair, papillae and so on. The results showed that glume micromorphological in Phaenosperma are different from type IV and type I, belonging to the sub-types f of type III. Sphaerocaryum glume micromorphological is different from sub-type c and type III, meet the standard of sub-type d of type II.We carried on the comprehensive analysis of Phytolith morphological and glume micromorphological through NJ method and constructed phylogenetic tree based on ITS, trnL-F sequence using molecular biology methods. The results showed that Phaenosperma belong to a same group with Deyeuxia, Agrostis, Calamagrostis,Avena, Poa, Puccinellia, corresponding to Pooideae. Among which, the type of Phaenosperma is independent as a small group. The type of Sphaerocaryum belong to a same group with Digitaria, Echinochloa, Isachne, Panicum, Paspalum and gathered together for a big group, corresponding to Panicoideae. Among them, Sphaerocaryum and Isachne gather together belonging to Isachneae.Based on the above results, we supposed that Phaenosperma should be placed into Pooideae as an independent of Phaenospermeae and the Sphaerocaryum should be classified as Isachneae belonging to the Panicodae.